28 research outputs found
Acoustic behaviour of two large terrestrial mammals in relation to resources maintenance and mating systems: wolf(<i>Canis lupus</i>) and red deer (<i>Cervus elaphus</i>) as model species
The high variability of vocalization is due to their function, the habitat where they evolved and the
physical constraints of the emitters. The aim of this study were to analyse the acoustic behaviour of two large terrestrial mammals, wolf (Canis lupus) and red deer (Cervus elaphus), in relation to resources maintenance and mating systems.
Firstly, I analysed the Italian wolf howl. I found two forms of howl; both types are uttered within the lowest frequencies of the wolfâs vocal range, confirming the acoustic adaptation hypothesis, and thus, that low frequencies are more useful for long distance communication. Moreover, I found a group vocal signature into the packs. This characteristic is constant both within biological season and between two consecutive years.
Secondly, I analysed the red deer mating calls. I described the vocal repertoire of Iberian red deer (C. e. hispanicus) males and I quantified variation of the roar of three free ranging subspecies.
Iberian red deer repertoire consists of four call types and presents the âshort common roarâ, absent in the repertoire of the others subspecies. Among red deer subspecies exists a strong vocal divergence: C.e. hippelaphus present the highest intra population variability, followed by C. e. corsicanus and C. e. hispanicus. Between subspecies, the highest bioacoustic differences were
found between C. e. hispanicus and C. e. corsicanus while this last population and C.e. hippelaphus are the most related subspecies
Genetic Distance from Wolves Affects Family Dogsâ Reactions Towards Howls
Domestication dramatically changes behaviour, including communication, as seen in the case of dogs (Canis familiaris) and wolves (Canis lupus). We tested the hypothesis that domestication may affect an ancient, shared communication form of canids, the howling which seems to have higher individual variation in dogs: the perception and usage of howls may be affected by the genetic relatedness of the breeds to their last common ancestor with wolves (âroot distanceâ) and by other individual features like age, sex, and reproductive status. We exposed 68 purebred dogs to wolf howl playbacks and recorded their responses. We identified an interaction between root distance and age on the dogsâ vocal and behavioural responses: older dogs from more ancient breeds responded longer with howls and showed more stress behaviours. Our results suggest that domestication impacts vocal behaviour significantly: disintegrating howling, a central, species-specific communication form of canids and gradually eradicating it from dogsâ repertoire
Genetic distance from wolves affects family dogsâ reactions towards howls
Domestication dramatically changes behaviour, including communication, as seen in the case of dogs (Canis familiaris) and wolves (Canis lupus). We tested the hypothesis that domestication may affect an ancient, shared communication form of canids, the howling which seems to have higher individual variation in dogs: the perception and usage of howls may be affected by the genetic relatedness of the breeds to their last common ancestor with wolves (âroot distanceâ) and by other individual features like age, sex, and reproductive status. We exposed 68 purebred dogs to wolf howl playbacks and recorded their responses. We identified an interaction between root distance and age on the dogsâ vocal and behavioural responses: older dogs from more ancient breeds responded longer with howls and showed more stress behaviours. Our results suggest that domestication impacts vocal behaviour significantly: disintegrating howling, a central, species-specific communication form of canids and gradually eradicating it from dogsâ repertoire
Barriers to psychological help-seeking in young men who have attempted suicide : an interpretative phenomenological analysis
The current paper reviews literature on help-seeking in relation to suicide and attempted suicide. An overview of the extensive research into risk factors associated with suicide is given highlighting the link between mental health problems and suicide. A minority of people with mental health problems seek professional help and even fewer people will go on to receive help from specialist mental health services. The same pattern is seen in those at risk of suicide. The majority will not be receiving specialist support at the time of their death although about half will have had recent contact with their GP. Reasons for not seeking help in times of emotional distress are discussed. Finally, clinical implications arising from the literature are addressed and suggestions are made for future research
Roaring high and low: composition and possible functions of the Iberian stag's vocal repertoire
We provide a detailed description of the rutting vocalisations of free-ranging male Iberian deer (Cervus elaphus hispanicus, Hilzheimer 1909), a geographically isolated and morphologically differentiated subspecies of red deer Cervus elaphus. We combine spectrographic examinations, spectral analyses and automated classifications to identify different call types, and
compare the composition of the vocal repertoire with that of other red deer subspecies. Iberian stags give bouts of roars (and more rarely, short series of barks) that are typically composed of two different types of calls. Long Common Roars are mostly given at the beginning or at the end of the bout, and are characterised by a high fundamental frequency (F0) resulting in poorly defined formant frequencies but a relatively high amplitude. In contrast, Short Common Roars are typically given in the middle or at the end of the bout, and are characterised by a lower F0 resulting in relatively well defined vocal tract resonances, but low amplitude. While we did not identify entirely Harsh Roars (as described in the Scottish red
deer subspecies (Cervus elaphus scoticus), a small percentage of Long Common Roars contained segments of deterministic chaos. We suggest that the evolution of two clearly distinct types of Common Roars may reflect divergent selection pressures favouring either vocal efficiency in high pitched roars or the communication of body size in low-pitched, high spectral density roars highlighting vocal tract resonances. The clear divergence of the Iberian red deer vocal repertoire from those of other documented European red deer populations reinforces the status of this geographical variant as a distinct subspecies
Acoustics of male rutting roars in the endangered population of Mesola red deer Cervus elaphus italicus
Mesola red deer are the only native red deer population remaining in peninsular Italy (Mattioli and Ferretti, 2014 and Zachos et al., 2014). Their peculiar morphological aspects and genetic makeup have earned them the qualification of Evolutionary Significant Unit (ESU), and the status of subspecies has recently been proposed. Despite this, their behaviour remains poorly documented. Because vocal behaviour, including rutting vocalisations, can provide useful phylogenetic signals (Cap et al. 2008), we present the first description of the main sexually selected male call. We find that roars of Mesola red deer are characterised by a relatively low average fundamental frequency (79 Hz) compared to that of most continental red deer populations, confirming the phenotypic originality of Mesola red deer and strengthening the case for its conservation. We also report that roars contain cues to identity, which could support individual recognition tools for monitoring this endangered population
Estimation of pack density in grey wolf (Canis lupus) by applying spatially explicit capture-recapture models to camera trap data supported by genetic monitoring
Abstract Background Density estimation is a key issue in wildlife management but is particularly challenging and labour-intensive for elusive species. Recently developed approaches based on remotely collected data and capture-recapture models, though representing a valid alternative to more traditional methods, have found little application to species with limited morphological variation. We implemented a camera trap capture-recapture study to survey wolf packs in a 560-km2 area of Central Italy. Individual recognition of focal animals (alpha) in the packs was possible by relying on morphological and behavioural traits and was validated by non-invasive genotyping and inter-observer agreement tests. Two types (Bayesian and likelihood-based) of spatially explicit capture-recapture (SCR) models were fitted on wolf pack capture histories, thus obtaining an estimation of pack density in the area. Results In two sessions of camera trapping surveys (2014 and 2015), we detected a maximum of 12 wolf packs. A Bayesian model implementing a half-normal detection function without a trap-specific response provided the most robust result, corresponding to a density of 1.21âÂąâ0.27 packs/100 km2 in 2015. Average pack size varied from 3.40 (summer 2014, excluding pups and lone-transient wolves) to 4.17 (late winter-spring 2015, excluding lone-transient wolves). Conclusions We applied for the first time a camera-based SCR approach in wolves, providing the first robust estimate of wolf pack density for an area of Italy. We showed that this method is applicable to wolves under the following conditions: i) the existence of sufficient phenotypic/behavioural variation and the recognition of focal individuals (i.e. alpha, verified by non-invasive genotyping); ii) the investigated area is sufficiently large to include a minimum number of packs (ideally 10); iii) a pilot study is carried out to pursue an adequate sampling design and to train operators on individual wolf recognition. We believe that replicating this approach in other areas can allow for an assessment of density variation across the wolf range and would provide a reliable reference parameter for ecological studies
Spectrograms illustrating the acoustic structure of the four call types.
<p>Long Common Roar (a), Long Common Roar with deterministic chaos (b), Short Common Roar (c) and series of Chase Barks (d).</p
Distribution of call types as a function of position within bouts.
<p>The most frequent position for each call type is highlighted in bold. LCR: Long Common Roar, LCRDC: Long common roars with deterministic chaos; SCR: Short Common Roar; CB: Chase Bark.</p